EP3862531A1

EP3862531A1 - Rotary engine with improved in-housing thermal load imbalance

Info

Publication number: EP3862531A1
Application number: EP20206548.8A
Authority: EP
Inventors: Eun Soo Ahn; Myung Kyu Kim
Original assignee: Tenergy Co Ltd
Current assignee: Tenergy Co Ltd
Priority date: 2020-02-05
Filing date: 2020-11-09
Publication date: 2021-08-11

Abstract

Rotary engine comprising:
- a housing (110) provided therein with a receiving space (S) to which a rotor (20) is rotatably coupled, the housing having an intake port (111) and an exhaust port (113);
- a heating unit (120) formed in a first section (A) of the housing (110), the intake port (111) being provided in the first section, the heating unit (120) being configured to heat the housing (110) cooled during intake and compression strokes; and
- a cooling unit (130) formed in a second section (B) of the housing, the exhaust port (113) being provided in the second section, the cooling unit (130) being configured to cool the housing (110) heated during combustion and exhaust strokes.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Applications No. 10-2020-0013868, filed on February 05, 2020 and No. 10-2020-0051903, filed on April 29, 2020 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety

BACKGROUND

Technical Field

The present disclosure relates to a rotary engine capable of improving a thermal load imbalance in a housing, in which a four-stroke cycle is performed, by applying a heating unit and a cooling unit to the housing.

Description of the Related Art

In general, a rotary engine is operated to rotate a rotor located in a section where fuel and air are mixed for combustion. Such a rotary engine was developed in 1951 by Felix Wankel of Germany.
Referring to FIG. 1, in principle, a rotary engine 1 is operated while a rotor 20 rotates along a curved surface called an epitrochoid within an engine housing 10.
The rotary engine 1 has a simple structure and high efficiency, so it can be made smaller in size than a piston engine. Thus, the rotary engine enables a vehicle equipped therewith to be reduced in weight, and is advantageous for the weight of the vehicle because it has a high degree of freedom for its installation position.
The piston engine generates a lot of vibration as its piston reciprocates, whereas the rotary engine has less vibration as it rotates in a certain direction.
On the other hand, the rotary engine 1 may be irregularly worn on the inner wall of its combustion chamber due to lack of durability, resulting in a poor rate of fuel consumption by incomplete combustion of fuel.
That is, the rotary engine 1 must be configured such that the contact surfaces between the rotor 20 and the housing 10 are in close contact with each other with a small gap therebetween so as to prevent leakage of fuel or oil while the rotor 20 continues to rotate in the housing 10.
In other words, if metals continue to rotate at high speed in a state in which they in close contact with each other, they may be worn due to friction therebetween. Accordingly, a sealing pad 21 called an apex seal is attached to each corner of the rotor 20 to protect the housing 10 and the rotor 20. However, this sealing pad 21 may be easily worn due to the characteristics of high-speed rotation as well.
Referring to FIG. 2, the rotary engine 1 operates in a four-stroke cycle (i.e., in the order of (a) intake → (b) compression → (c) combustion → (d) exhaust) while the rotor 20 rotates in one direction within the housing 10.
In this case, the intake section 11 and exhaust section 13 in the housing 10 have different temperatures while the four-stroke cycle is performed in the housing 10. That is, since the housing 10 has a structure in which the intake section 11 is continuously cooled and the exhaust section 13 is continuously exposed to high temperature and high pressure, the temperature variation in each region of the housing is large.
The durability of the housing 10 having the above structure is weakened due to thermal expansion and contraction, which may lead to problems such as abrasion of the inner peripheral surface of the housing 10 or gas leakage and engine damage.

[Patent Document]

Korean Patent Application Publication No. 10-2002-0061929 (published on July 25, 2002 )

SUMMARY

The present disclosure has been made keeping in mind the above problems occurring in the related art, and the present disclosure is intended to propose a rotary engine capable of attaining a uniform temperature distribution in a housing, in which a four-stroke cycle is performed, by applying a heating unit and a cooling unit to the housing, thereby improving a thermal load imbalance in the housing.
Additional advantages, objects, and features of the disclosure will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the disclosure.
In accordance with an aspect of the present disclosure, there is provided a rotary engine that includes a housing provided therein with a receiving space to which a rotor is rotatably coupled, the housing having an intake port and an exhaust port, a heating unit formed in a first section of the housing, the intake port being provided in the first section, the heating unit being configured to heat the housing cooled during intake and compression strokes, and a cooling unit formed in a second section of the housing, the exhaust port being provided in the second section, the cooling unit being configured to cool the housing heated during combustion and exhaust strokes.
The heating unit may heat the first section by circulating some of exhaust gas, discharged through the exhaust port, along a heating line installed in the first section.
The cooling unit may cool the second section by circulating coolant along a cooling line installed in the second section.
The cooling line may include a main passage provided on one side thereof with an inlet, and a plurality of branch passages branched from the other side of the main passage.
The branch passages may include a first circulation part disposed in a high-temperature region of the second section, and a second circulation part disposed in a middle-low temperature region of the second section.
The branch passages may each further include a temperature sensor and a flow control valve, to allow the flow rates of the coolants supplied to the respective branch passages to be adjusted differently according to the temperature of the second section.
When the first circulation part has a higher coolant temperature than the second circulation part, some of the coolant passing through the second circulation part may be supplied to the first circulation unit.
The temperature sensor may be installed at each outlet of the branch passages, and the flow control valve may be installed at each before-branch inlet of the branch passages.
It is to be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide further explanation of the disclosure as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a cross-sectional view illustrating an internal structure of a typical rotary engine;
FIG. 2 is a view illustrating a sequence of operation of the rotary engine of FIG. 1;
FIG. 3 is a view illustrating an internal configuration of a rotary engine, whose housing is provided with a heating unit and a cooling unit, according to the present disclosure;
FIG. 4 is a perspective view illustrating the heating unit according to the present disclosure;
FIG. 5 is a perspective view illustrating the cooling unit according to the present disclosure; and
FIG. 6 is a view illustrating circulation of coolant through the cooling unit according to the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Exemplary embodiments of the present disclosure will be described below in more detail with reference to the accompanying drawings.
Regarding the reference numerals assigned to the elements in the drawings, it should be noted that the same elements will be specified by the same reference numerals, wherever possible, even though they are illustrated in different drawings.
FIG. 3 is a view illustrating an internal configuration of a rotary engine, whose housing is provided with a heating unit and a cooling unit, according to the present disclosure. FIG. 4 is a perspective view illustrating the heating unit according to the present disclosure. FIG. 5 is a perspective view illustrating the cooling unit according to the present disclosure.
Referring to FIG. 3, a rotary engine 100 with improved in-housing thermal load imbalance according to an exemplary embodiment of the present disclosure may include a housing 110, a heating unit 120, and a cooling unit 130.
The configuration of the present disclosure will be described in detail as follows.
First, the housing 110 may form a main body of the rotary engine 100. The housing 110 may be provided therein with a receiving space S, and a rotor 20 may be eccentrically coupled to the receiving space S.
The housing 110 may have an intake port 111 provided on one side thereof. A predetermined ratio of fuel and air required to operate the rotary engine 100 may be injected through the intake port 111.
An exhaust port 113 may be provided beneath the intake port 111 so as to allow exhaust gas after having been subjected to a four-stroke cycle (intake → compression → combustion → exhaust) (see FIG. 2) to be discharged to the outside.
In this case, the receiving space S of the housing 110 may have an inner peripheral surface formed with a predetermined curvature so as to correspond to the rotation trajectory of the rotor 20. Since the process in which the four-stroke cycle is performed in the housing 110 by eccentric rotation of the rotor 20 is a known technique, a detailed description thereof will be omitted.
The heating unit 120 may be formed in a first section A of the housing 110, wherein the intake port 111 is provided in the first section A. The heating unit 120 may heat the housing 110 cooled during the intake and compression strokes of the four-stroke cycle.
Specifically, the heating unit 120 may circulate the exhaust gas, which is discharged through the exhaust port 113, along a heating line 121 formed in the first section A. Thus, the heating unit 120 may heat the first section A of the housing 110.
Referring to FIG. 4, the heating line 121 may be provided in a form in which a hollow pipe is bent to correspond to the area of the first section A (see FIG. 3). Both sides of the heating line 121 may be provided with an exhaust inlet 123 and an exhaust outlet 125 which communicate with the exhaust port 113. Accordingly, some of the exhaust gas discharged through the exhaust port 113 may be circulated along the heating line 121 through the exhaust inlet 123 and then discharged back to the exhaust port 113 through the exhaust outlet 125.
Referring to FIG. 3 again, the cooling unit 130 may be formed in a second section B of the housing 110, wherein the exhaust port 113 is provided in the second section B. The cooling unit 130 may cool the housing 110 heated during the combustion and exhaust strokes of the four-stroke cycle.
Specifically, the cooling unit 130 may cool the second section B by circulating coolant along a cooling line 131 formed in the second section B. The cooling line 131 may be branched into a plurality of lines in order to improve cooling efficiency. Referring to FIG. 5, the cooling line 131 may include a main passage 133, which is provided on one side thereof with a coolant inlet 131a, and a plurality of branch passages 135 branched from the other side of the main passage 133. The branch passages 135 are merged back into one coolant outlet 131b. Accordingly, the coolant, which is supplied through the coolant inlet 131a and then circulated along the branch passages 135, may be discharged through the coolant outlet 131b to the outside of the housing 110.
Referring to FIG. 6, the branch passages 135 may include a first circulation part 135a disposed in a high-temperature region (where a ignition plug is installed) of the second section B in which the combustion stroke is mainly performed, and a second circulation part 135b disposed in a middle-low temperature region of the second section B, namely, around the high-temperature region.
In addition, each of the branch passages 135 may be provided with a temperature sensor 137 and a flow control valve 139. The temperature sensor 137 may be installed at each outlet of the branch passages 135, and the flow control valve 139 may be installed at each before-branch inlet of the branch passages 135. Thus, the flow rates of the coolants supplied to the respective branch passages 135 may be adjusted differently according to the temperature of the second section B. For example, when the coolant temperature in the first circulation part 135a is higher than that in the second circulation part 135b, a controller (not shown) may control some of the coolant passing through the second circulation part 135b to be supplied to the first circulation unit 135a.
As described above, the rotary engine 100 with improved in-housing thermal load imbalance according to the present disclosure can attain a uniform temperature distribution in the housing 110, in which the four-stroke cycle is performed, by applying the heating and cooling units 120 and 130 to the housing 110, thereby improving a thermal load imbalance in the housing 110.
As is apparent from the above description, the rotary engine having the above-mentioned configuration according to the present disclosure can attain a uniform temperature distribution in the housing, in which the four-stroke cycle is performed, by applying the heating and cooling units to the housing. Therefore, it is possible to improve a thermal load imbalance in the housing.
Although the present disclosure has been described with respect to the illustrative embodiments, it will be apparent to those skilled in the art that various variations and modifications may be made without departing from the spirit and scope of the disclosure as defined in the following claims.

Claims

A rotary engine comprising:
a housing provided therein with a receiving space to which a rotor is rotatably coupled, the housing having an intake port and an exhaust port;

a heating unit formed in a first section of the housing, the intake port being provided in the first section, the heating unit being configured to heat the housing cooled during intake and compression strokes; and

a cooling unit formed in a second section of the housing, the exhaust port being provided in the second section, the cooling unit being configured to cool the housing heated during combustion and exhaust strokes.
The rotary engine according to claim 1, wherein the heating unit heats the first section by circulating some of exhaust gas, discharged through the exhaust port, along a heating line installed in the first section.
The rotary engine according to claim 1 or 2, wherein the cooling unit cools the second section by circulating coolant along a cooling line installed in the second section.
The rotary engine according to claim 3, wherein the cooling line comprises:
a main passage provided on one side thereof with an inlet; and

a plurality of branch passages branched from the other side of the main passage.
The rotary engine according to claim 4, wherein the branch passages comprise:
a first circulation part disposed in a high-temperature region of the second section; and

a second circulation part disposed in a middle-low temperature region of the second section.
The rotary engine according to claim 4 or 5, wherein the branch passages each comprise a temperature sensor and a flow control valve, to allow the flow rates of the coolants supplied to the respective branch passages to be adjusted differently according to the temperature of the second section.
The rotary engine according to claim 5 or 6, wherein when the first circulation part has a higher coolant temperature than the second circulation part, some of the coolant passing through the second circulation part is supplied to the first circulation unit.
The rotary engine according to claim 6, wherein:
the temperature sensor is installed at each outlet of the branch passages; and

the flow control valve is installed at each before-branch inlet of the branch passages.